Calculating Stress And Deformation Of Anti-slide Pile With Anchor Based On Weighted Residual Method

Landslide is a worldwide geological disaster,it seriously threatens the living environment of human beings and hinder the development of human.Therefore landslide management is a basic and important research topic.Anti-slide pile with prestressed cable is an effective landslide control method,it has so many advantages,such as small deformation,strong anti-sliding ability and convenient construction process,which is used in landslide treatment widely.Domestic and foreign scholars have conducted extensive research on slopes and anti-slide pile with prestressed cable by model experiments,in-situ tests,numerical simulations,and theoretical analysis.Therefore many useful results were obtained,which provided powerful technical support for slope treatment projects.In order to further investigate the slope sliding mechanism,the interaction relationship and theory of calculation model between cable,pile and soil of anti-slide piles with prestressed anchor cables,the calculational theory of force and deformation was studied with the support of National Natural Science Foundation(41572298).The main works and results of this paper are summarized as follows:(1)According to the characteristics of progressive slope instability in actual projects,the strain softening parameter are introduced,the functional about s oil strength parameters(c,?)with different reduction factors are established based on strain softening parameter,and improving the existing slope stability analysis methods based on the limit equilibrium theory.A formula for calculating the landslide thrust is derived based on simplified Bishop method and transfer coefficient method under soil strength parameters are not reduced synchronously.Finally,a formula for calculating the overall safety factor of the slope is proposed,reflecting the different contributions of the cohesion and friction angle to the slope stability.(2)Combining the characteristics of control differential equation of anti-slide pile and by employing 5th B-spline function as trial function of the anti-slide pile,the subdomain least square collocation weighted residual method was adopted,the method for calculation stress and deformation of anti-slide pile based on weighted residual method is established.The stability of the slope was analyzed based on the transfer coefficient method under strength parameters reduction with same ratio and different ratio.Simultaneously,undering the influence of landslide thrust which obtained by the two methods,the stress and deformation of the anti-slide pile are calculated based on weighted residual method.By analyzing the calculation results,it is believed that the improved slope stability analysis method can provide a reference for engineering design.(3)To resolve the deficiencies of the calculation model for anti-sliding pile with prestressed anchor cable,a calculation model is established respectively in applying prestress and landslide thrusting stage according to the actual construction process and loading conditions of anti-slide pile with anchor cable.The impact of prestress loss of anchor cable and displacement of pile in construction stage on the displacement compatibility equation of pile-anchor cable is considered.Meanwhile,the method of calculation of the internal forces and deformation of anti-sliding pile with prestressed anchor cable is established based on weighted residual method.A calculation procedure of anti-slide pile with anchor cable is created based on Matlab platform,which was used to analyze engineering examples already.The results are compared with those of the conventional calculation model.It is shown that the improved model can not only well embody the effect of the special process of anti-slide pile with anchor cable bearing active load in the prestressed stage on the displacement compatibility equation of pile-anchor cable,but also take into account the prestress lose of upper anchor cable which is caused by the lower anchor cable in prestressed stage properly.What is more,compared to the conventional calculation model,the improved model is more in line with the engineering practice.